[29271] in North American Network Operators' Group

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Re: in-addr.arpa?

daemon@ATHENA.MIT.EDU (trall@almaden.ibm.com)
Thu Jun 15 11:12:51 2000

From: trall@almaden.ibm.com
To: Hank Nussbacher <hank@att.net.il>
Cc: nanog@merit.edu
Message-ID: <872568FF.00527C68.00@d53mta03h.boulder.ibm.com>
Date: Thu, 15 Jun 2000 00:36:09 -0700
Mime-Version: 1.0
Content-type: text/plain; charset=us-ascii
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Errors-To: owner-nanog-outgoing@merit.edu




On 06/14/2000 at 08:04:34 ZE2, Hank Nussbacher <hank@att.net.il> wrote:
> Why would 216.136.44.104 do something like this?
>   14 ip104.44.136.216.in-addr.arpa (216.136.44.104) [AS 4323] 404 msec
400

Do you mean why is its name shown as ip104.44.136.216.in-addr.arpa?

It is a strange name, but it simply means that the 44.136.216.in-addr.arpa
zone has a record like this:

104.44.136.216.in-addr.arpa.   PTR ip104.44.136.216.in-addr.arpa.

Doing a whois on 216.136.44, we find:

Internet Connect, Inc. (NETBLK-INCNET-BLK-4) INCNET-BLK-4
  216.136.0.0 - 216.136.127.255
Time Warner Telecom, Inc. (NETBLK-TWTC-BLOCK-01) TWTC-BLOCK-01
  216.136.32.0 - 216.136.63.255
Andrew F. Capoccia Law Centers (NETBLK-TWTC-ALBY-C-CAPOCCI-0)
TWTC-ALBY-C-CAPOCCI-0
  216.136.44.0 - 216.136.44.15
Farm Family Casualty Ins. (NETBLK-TWTC-ALBY-C-FARMFAM-0)
TWTC-ALBY-C-FARMFAM-0
  216.136.44.16 - 216.136.44.31
Global Spec (NETBLK-TWTC-ALBY-C-GLBLSPC-0) TWTC-ALBY-C-GLBLSPC-0
  216.136.44.32 - 216.136.44.47
James McGuinness & Assoc (NETBLK-TWTC-ALBY-C-JMCGNSS-0)
TWTC-ALBY-C-JMCGNSS-0
  216.136.44.48 - 216.136.44.63
Learn Linc (NETBLK-TWTC-ALBY-C-LRNLINC-0) TWTC-ALBY-C-LRNLINC-0
  216.136.44.96 - 216.136.44.127
LaCorte Companies Inc (NETBLK-TWTC-ALBY-C-LACORTE-0) TWTC-ALBY-C-LACORTE-0
  216.136.44.128 - 216.136.44.159
New Horizons Computer Learning (NETBLK-TWTC-ALBY-C-NEWHORZ-0)
TWTC-ALBY-C-NEWHORZ-0
  216.136.44.168 - 216.136.44.175
Rupprecht %26 Patashnick Co. Inc. (NETBLK-TWTC-ALBY-C-RUPPPAT-0)
TWTC-ALBY-C-RUPPPAT-0
  216.136.44.176 - 216.136.44.191
Phelan%2C Burke %26 Scolamiero (NETBLK-TWTC-ALBY-C-PBSLAW--0)
TWTC-ALBY-C-PBSLAW--0
  216.136.44.192 - 216.136.44.199

and conclude that Time Warnet Telecom has subdivided their /19 into a bunch
of /28s (or smaller).  Rather than hassle with doing classless in-addr.arpa
delegation (rfc2317?) they've just used placeholder nanes for all the
addresses.

Tony Rall




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